Thermal insulation



1965 w. R. GASTON ETAL 3,222,243

THERMAL INSULATION Filed July 11. 1962 if I I INVENTORS WILLIAM A.64sT0/v 3 BY DAV/0 0. RICHARDS ,4 7' TOR/V5 vs the edges.

United States Patent 3,222,243 THERMAL INSULATION William R. Gaston,Anderson, S.C., and David 0. Richards, Haddonfield, N.J., assignors toOwens-Corning Fiberglas Corporation, a corporation of Delaware FiledJuly 11, 1962, Ser. No. 209,022 4 Claims. (Cl. 161113) This inventionrelates to improved thermal insulation, and more particularly to thermalinsulation comprising mineral fibers in unique combination with areflective foil and an impervious vapor barrier.

In accordance with the prior art, one popular type of thermal insulationcomprised a batt of loose mineral fibers, such as glass fibers,contained in a fully enclosed reflective insulation envelope comprisinga laminate of kraft paper as a base and aluminum foil as an exposedreflective coating material. As is well known, these products are lightin weight and very bulky, thus requiring compression packaging forshipping.

One common method for compression packaging such thermal insulationcomprises stacking layers of the insulation together at the end of theproduction line; then compressing the layers to about ten to fifteenpercent of original thickness; and sliding the compressed mass axiallyor longitudinally from between the compression platens into a retainingbag of heavy kraft paper. Unfortunately, when the product is socompressed, it takes a permanent set along the crumpled edges or sidesand does not recover full thickness after removal from the compressionpackage. Further, in compression packaging and in installation betweenfloor or ceiling joists or wall studs, the foil and kraft are oftenbadly bent and torn open because of the weak nature and sensitivity ofthe previously crumped foil to abrasion. The result is improper contactbetween such edges and either a ceiling or floor joist or wall stud atthe installation site. As will be obvious to those skilled in the art,such improper contact provides heat convection passages causing lossesof thermal elficiency or lower K- factor of the insulating combination.

Further, the all-encircling envelope requires added material costs inthe kraft paper-foil laminate used to cover The result is a moreexpensive product. Still further, the foil provided a heat transferbridge between the hot and cold sides of the batt.

To compensate for the loss in thickness recovery, the manufacturer hasbeen forced to produce the material oversize,.entailing greater cost ofmaterials and manufacturing energy with heavier shipping costs, thusburdening manufacturing efliciency.

To alleviate one of these difiiculties, a step forward was made in theart by omitting the foil from the kraft paper backing along the edges ofthe fibrous batt, thus leaving only a relatively non-conductive bridgeof kraft paper exposed at the edges. It has been found that this productis somewhat more successful than the prior full foil enclosed product inthermal efiiciency. However, the defects of compression packaging,shipping, installation and the like are retained by the product. Thus,even the kraft-covered edge product is not fully satisfactory in that,although somewhat more abuse-resistant than the foillaminate fullyenclosed material, it is still subject to substantial edge damage inpackaging, shipment and installation. Inefliciencies in installationresult from the torn or crumped kraft paper edges which produceconvection pockets, as mentioned above. The result is a substantial lossin insulating efficiency, counterbalancing the gain made by omitting theheat-conductive bridge.

Accordingly, an important step forward in the art would be provided by anovel insulation material which has higher thermal efiiciency than priorart related products;

ice

that uses less material for greater economy of manufacture; thatovercomes convection leaks; that provides better recovery fromcompression packaging; and other advantages.

It is accordingly an important object of the present invention toprovide a novel thermal insulation material.

A further object is to provide a novel thermal insulation material madeof mineral fibers in unique combination with a reflective vapor barrierand a supporting foil.

A still further object is to provide a novel thermal insulation materialof light weight having improved thickness recovery from compressionpackaging, that is more economical to manufacture, yet having higherthermal efficiency than comparable products.

A still further object is to provide an improved thermal insulationmaterial combining specific mineral fibers with one or more reflectivefoils for improved insulation eificiency, and being vented in a uniquemanner for removal of condensate moisture, thus providing improveddurability and longer life with a higher level of retained thermalinsulation efficiency.

Another object of the present invention is to provide an improvedthermal insulation comprising mineral wool fibers wherein the edges ofthe fibrous batt are free of enclosing material and wherein a foil-kraftlaminate or reflective foils is adhesively secured in a unique manner toeach major face of the batt without edge enclosing portions.

A further object is to provide an improved method of producing fibrousglass mat thermal insulation materials, unique in the manner ofcombining particularly laid fibers with a particularly applied stripadhesive to provide product resilience and improved breathingcharacteristics for vapor removal.

A further object is to provide an improved thermal insulation materialmade of glass fibers and having both major surfaces covered with areflective metal foil and raw, uncovered edges whereby the edges moreeffectively abut building members to prevent convection heat transfer.

It is a further important object to provide a thermal insulationmaterial which effectively reflects radiant heat and which furthereffectively reduces the transmission of convection heat.

Other objects of this invention will appear in the following descriptionand appended claims, reference being had to the accompanying drawingsforming a part of this specification wherein like reference charactersdesignate corresponding parts in the several views.

FIGURE 1 is a perspective view of one embodiment of the novel compositethermal insulation of the present invention, utilizing an imperforatefoil-kraft-asphalt laminate on the hot side and a perforate foil-kraftlaminate on the cold side with strip asphalt adhesive, and nailing tabson the hot side;

FIGURE 2 is a perspective view of another embodiment of the inventionutilizing a foil vapor barrier bonded with strips of adhesive on the hotside and a perforated foil-kraft laminate on the cold side, withfastening tabs extending from the edges of both major surfaces;

FIGURE 3 is a perspective view of still another embodiment of theinvention utilizing an imperforate kraftasphalt laminate vapor barrieron the hot side and employing a perforated kraft-reflective foillaminate on the cold side with fastening tabs on the hot side only;

FIGURE 4 is a fragmentary section View illustrating an installedcondition of the prior art all-enclosing envelope product, forcomparison with the installed views of FIGURES 5-9 of the presentinvention;

FIGURE 5 is a fragmentary section view similar to FIGURE 4, but showingthe improved installation of one embodiment of the present invention,installation having been made from the inside as in new buildingconstruction;

FIGURE 6 is a fragmentary section view similar to FIGURE illustratinginstallation of one embodiment of the present invention from the outsideas in old building construction or optionally in new buildingconstruction;

FIGURE 7 is a fragmentary section view illustrating the improvedinstallation provided by a product similar to that of FIGURE 2, havingfastening tabs along both major surfaces with both sets of tabs secured,as in highest quality new building construction.

FIGURE 8 is a fragmentary section view similar to FIGURE 7 illustratingthe improved installation provided by a product typified by FIGURE 2,having fastening tabs on both major surfaces, but with only the tabs onthe cold side secured, illustrating highest quality old buildinginstallation; and

FIGURE 9 is a fragmentary section view in enlarged detail illustratingthe manner in which the perforations are formed in the cold sidekraft-foil laminate by splayed piercing.

Before explaining the present invention in detail, it is to beunderstood that the invention is not limited in its application to thedetails of construction and arrangement of parts illustrated in theaccompanying drawings, since the invention is capable of otherembodiments and of being practiced or carried out in various ways. Also,it is to be understood that the phraseology or terminology employedherein is for the purpose of description and not of limitation.

PERSPECTIVE VIEW Briefly the present invention relates to an improvedthermal insulation material comprising high-grade long staple mineralfibers in unique combination with reflective foils, and held together ina particular manner to permit free exposure of the raw edges, thusproviding improved thermal insulation eificiency, reduced convection ofheat, improved flexibility of installation, greater economy ofproduction and improved thickness recovery from compression packaging.

Accordingly, the present invention provides a unique product and methodfor its manufacture based on the use of a particular manner of laying upthe fibrous batt itself and combining it with a vapor barrier andreflective material in a unique strip adhesive application technique fora resilient, substantially abuse-resistant product.

THE INVENTION The embodiment of FIGURE 1 The embodiment of FIGURE 1comprises a fibrous mat 10 or batt of long staple fibers, preferably ofmineral wool, and more particularly of fine glass fibers produced as bydisc spinning or by flame attenuation and with the fibers bonded to oneanother at the point of intersection as by a thermosetting resin,applied by spraying an aqueous dispersion of the resin into a collectingchamber in which the fibers are directed during formation of the batt,and subesquently cured in a heated oven with provision being made forcontrolling the thickness of the batt during the curing operation.

Also, in the embodiment of FIGURE 1, a foil-kraft laminate 12 isprovided on the hot side, that is on the side of the insulation that isinstalled toward the interior of the building. The foil-kraft laminate12 comprises a thin foil 14 of reflective character, such as aluminumfoil, or equivalent, bonded as by sodium silicate or other suitableagent to a sulphite kraft paper 16.

In this embodiment of the invention, the foil-kraft laminate is bondedto one major surface of the fibrous batt 10 by means of a continuouslayer of asphalt 18. It will be noted that the foil-kraft laminate iswider than the batt 10 to provide nailing or fastening tabs along eachedge.

In this embodiment of the present invention, the foil 14 provides afirst vapor barrier and the asphalt a second vapor barrier, so that inthe event of shipping or handling if any holes are accidentally made inthe foil, the continuous asphalt coating 18, being attached to the otherside of the tough kraft layer 16 will provide a secondary safeguard fora hot side vapor seal.

To the other side of the batt 10, there is secured a perforatefoil-kraft laminate 22, comprised of outer foil 24 and inner kraft 26,bonded together as by sodium silicate or other suitable and economicalwater-resistant bonding agent.

The perforate foil-kraft laminate 22 has small breather holes 28uniformly distributed over the entire surface, as by punching orpiercing, to be subsequently described. Where punching is utilized,actual bits of the laminate are removed; however, where piercing isutilized the material is retained in place for the full reflectiveeffect of the retained foil.

In this embodiment of the invention, it will be noted that the cold sideperforate foil-kraft laminate 22 covers only the cold-side major surfaceof the batt 10, and thus does not extend beyond the edges, as does thehot-side foil-kraft laminate 12.

An important aspect of the FIGURE 1 embodiment, as well as the otherembodiments to be later described, is the manner in which the cold sidelaminate 22 is secured to the fibrous batt 10. Reference numeral 30illustrates spaced longitudinally extending strips of asphalt placed onthe underside of the kraft paper 26 to bond the laminate 22 and thecold-side major surface of the batt 10 together. By so operating, themajor portion of the breather holes 28 will be left open so that thecold side of the structure can breath for removal of moisture, such asformed by condensation.

Summary of FIGURE From the foregoing, it will be understood that ahighly effective thermal barrier is provided in accordance with thepresent invention by utilizing a double vapor barrier in the form offoil and continuous asphalt layer, and a double reflector in the form ofexposed reflective foils on each surface of the fibrous glass batt. Notealso that free breathing characteristics are provided. Still further, ahighly effective convection heat reducer is provided by the fibrous batt10, containing a multitude of tiny air pockets or pores, a knowneffective insulator; with the batt integrity being preserved by longstaple mineral fibers retained in position by a bonding agent at theintersections of the fibers, thus insuring an open structure to the airpockets over a long product life.

The manner in which improved installation is provided in accordance withthe present embodiment will be subsequently described.

From the foregoing it will also be observed that the lateral edges 32 ofthe fibrous batt 10 are exposed, providing full thickness recovery fromcompression packagmg.

The embodiment of FIGURE 2 A modification of the present inventionresides in the use of a substantial foil 34 on the hot-side of thefibrous batt 10, as an equivalent to the foil-kraft laminate 12 ofFIGURE 1; the stronger foil replaces the strength and support of thekraft for a lighter foil.

In this embodiment of the invention, it is also possible to use stripsof asphalt 30 on the hot-side, because of the highly effective vaporbarrier characteristics of the heavier foil 34. By operating in thismanner, the resilient characteristic of the batt 10 is utilized toprovide conformance to the flexing of the foil 34, thereby substantiallydecreasing the possibility of rupturing the foil during manufacturing,packaging, shipping or installation.

By operating in this manner, the heavier foil 34 may be found to beapproximately of the same cost as the lighter foil 14 and kraft backingsupport 16 and bonding material and processing technique steps asrequired in producing the laminate 12 of FIGURE 1.

In this second embodiment of the invention, the coldside is covered withthe same type of perforate foil-kraft laminate 22 as used in FIGURE 1,comprising an outer foil 24, inner kraft 26, perforated as at 28, andbonded as by strips of asphalt adhesive 30. However, it will be notedthat the cold-side laminate 22 can be approximately of the same width asthe foil 34, thus extending beyond the lateral edges 32 of the batt toprovide cold-side nailing tabs 36, in addition to the hot-side nailingtabs 20, provided by the foil 34.

The advantages inherent in this type of structure, as regards theeffective utilization of the nail tabs 36, will be brought outhereinafter.

The thermal characteristic of this product is the same as that of theembodiment of FIGURE 1, by virtue of the use of exposed reflective foilon each of the major surfaces of the batt 10 to provide effectivereflection of radiant energy, in combination with the fibrous batt 10,which provides effective reduction of convection heat.

The embodiment of FIGURE 3 A more economical embodiment of the novelinsulation of the present invention resides in the use of kraft paper 38in combination with a continuous layer 18 of asphalt for bonding to thehot-side of the batt 10, providing the extended attachment tabs 20. Itwill be noted that in this embodiment of the invention, the asphaltlayer 18 provides the vapor barrier on the hot-side.

On the cold-side, the foil-kraft laminate 22 is also used with stripasphalt bonding to provide proper breathing through the holes 28. Itwill be noted in this embodiment, as in the previously describedembodiments, that the lateral edges 32 of the batt 10 are exposed forimproved thickness recovery after compression packaging.

In this embodiment of the invention, advantage is taken of thereflective nature of the foil 24 of the laminate 22 to cut down solarheat radiation inwandly from the exterior of a building during summer.This insulation is particularly adapted for Warmer climates, such as thesouthern portion of the United States, where solar radiation is agreater factor than internal heat-loss.

In this embodiment of the invention, elfective use is also made of thebatt 10 in reducing convection heat. Thus, a highly elfective insulationfor more moderate climates is provided, having the improved thicknessrecovery characteristic by virtue of the omission of any restrictionfrom the raw edges 32.

Installation advantages of the present invention Illustration of thedisadvantages of the prior art. FIGURE 4 illustrates a typical prior artinstallation, wherein the insulation material comprised a loose andunbonded batt of mineral fibers 40, contained within an all-enclosingenvelope 42. It will be noted that the hot side layer 44 of the envelopewas made of kraft paper with a coating of asphalt 46 thereon comprisingthe vapor barrier. The cold side covering 48 is shown as it completelyencased the sides or lateral edges of the batt and was provided withbreather holes 50 on the cold-side or surface. Note also that the edgeof the cold-side covering 48 and the edge of the kraft paper hot-sidelayer 44 are interleaved to form the conventional nailing tab 52,through which a nail 54 is passed for installation.

Note that the portion of the cold-side covering 48 covering the lateraledge of the batt 40, namely designated by the reference numeral 56, isseverely wrinkled and not in perfect abutting contact with the adjacentbuilding member, typified by a ceiling joist 58. Thus, convectioncurrents are readily set up for heat transfer between the hot-side 44and the cold-side 48 in the void spaces 60 provided between the joist 58and the wrapping portion 56. Thus heat penetrating the plaster layer 62into the air space 64 will travel by convection along the ceiling joist58 and be lost in accordance with this typical prior art installation,brought about by crushing of the edge-covering portion 56 duringcompression packaging and handling.

Improved installation 0 FIGURE 5 In contrast to the deficienciesinherent in the prior art as shown in FIGURE 4, FIGURE 5 illustrates animproved installation in accordance with the present invention, namelythe embodiment of FIGURE 1. Note that perfect abutting relation isprovided between the exposed lateral edge 32 and the building joist 58,thus eliminating convection transfer at this vital point ofinstallation.

The installation 0 FIGURE 6 FIGURE 6 illustrates the installation of anembodiment of the invention wherein the nailing tab 66 is on thecold-side foil-kraft laminate 22, in contrast to the prior descriptionsof FIGURES l and 3, where the nailing tabs 20 are on the hot-side battsupport.

The advantage of the FIGURE 6 embodiment is that after-buildinginstallation is provided in accordance with the present invention; thusan old, uninsulated structure can be insulated. As is well-known, theattic space in many houses is accessible, and particularly in some areascontractors are known to leave the attic uninsulated. Noting the lostheat after living in the dwelling for a time, the occupant is oftendesirous of reducing the heat loss in cooler seasons for greater fueleconomy, as well as heat entry during the hot seasons from the attic forgreater comfort. Thus he desires to insulate the attic after thedwelling is built. In accordance with FIGURE 6, this is readily done andit will be noted that nailing at 68 provides for installation from theattic space, the nail tab 66 serving as a gage for preservation of theair space 64, which of course the workman cannot see.

An advantage of this type of installation is that the hot-side laminate22 is stretched or placed under slight tension to form a supportingbridge for the batt 10, and thus sustains the lower foil-kraft laminate12 against in situ sagging, and thereby preserves the air space 64 overlong life. As is well-known, the air space 64 is an important factor inoverall thermal insulation efliciency and its preservation is therebyenhanced in accordance with the present invention.

The installation of FIGURE 7 The installation of FIGURE 7 utilizes thetype of double tab nailing structure, described for the embodiment ofFIGURE 2, and, as shown, results in a very high quality installationwhen both sets of nailing tabs 20 and 36 are secured to the buildingjoists 58 in new construction where both sides are accessible.

The cold-side set of tabs 36, when nailed as at 70, serve to stretch ortension and support the cold-side foil-kraft laminate 22 as discussedfor the FIGURE 6 embodiment, and prevent sagging and compaction of thebatt 10, thus preserving full thickness with high heat insulationproperties over extended periods of in situ use.

Also, the nailing as at 54 also converts the foil-kraft laminate 12 intoa supporting bridge for the batt 10, cooperating with the upper laminate22 to preserve the air space 64.

Thus, by the present invention the highest efliciency life of theproduct is preserved.

The installation of FIGURE8 The double tab structure of FIGURE 7 is alsohighly effective in after installation as in older buildings, as shownin FIGURE 8. In this type of installation, of course, the installerworks from the attic side, using the tabs 36 as a gage for establishingthe concealed air space 64. As discussed above, nailing at 70 tensionsthe laminate 22 to form a supporting bridge for the batt 10 and alsosupports through the batt the hot-side laminatevapor barrier 12. Inmaking this installation the installer holds back the tabs 20 beforeplacing the batt between the joist 58. The tabs 20 will tend to resumetheir former position and swing in an arcuate manner to a generallyperpendicular bridge-like wall with the terminal edge abutting theplaster layer 62 and providing support adjacent the joist 58 for moreperfect and intimate contact between the exposed lateral edges 32 of thebatt and the building member 58. Thus, the full Width of the air space64 is carefully preserved and long life thermal efficiency is enhancedin accordance with this after installation.

The pierced barrier of FIGURE 9 FIGURE 9 illustrates a method embodimentof the invention where the cold side laminate 22 may be pierced as byblades or needles to both preserve the full surface of the foil-24 forits reflective characteristics and also provide small open pockets 72down into the fibrous mat for improved breathing efficiency.

In accordance with this embodiment, the perforating operation iseffected suitably by a needled roller just as the product leaves theassembly line. Thus, the laminate 22 is perforated in situ.

Extended scope of invention An important feature of the products of thepresent invention resides in the use of a coherent fibrous battcontaining long staple fibers, and more preferably of glass fibershaving appreciable length. These fibers are preferably oriented ingenerally parallel planes and laid in transverse directions upon oneanother with the intersections between the fibers being bonded by asuitable material such as a thermosetting phenolic resin and thuspresenting substantial batt integrity.

More particularly, glass fibers having diameters in the range of up toabout fifty microns and lengths in the range up to about three inches,made either by a spinning disc process or by flame attenuation arepreferred, and have been found to give unexpected performance. The longnature of the glass fibers utilized in accordance with the presentinvention render the product unique in that the fibers are maintainedwithin the mat without need for complete enclosure as contrasted to theloose prior art structures. The binder is highly effective in preservingfiber-to-fiber spacing relationship and in preserving the air cells inuniform distribution throughout the batt.

It is this combination of factors that makes it possible to omit eitherthe paper or paper-foil bridges that have heretofore characterized theproducts of the prior art, with their inherent difficulties ofinstallation because of the crumbling along the lateral edges asindicated in FIGURE 4.

Other long staple fibers, essentially equivalent in body dimension tothose of the glass fibers described above can be employed. However,since other mineral fibers such as mineral wool fibers or the slagfibers, do not generally encompass these characteristics because oftheir extremely short fiber length and brashy, brittle nature, theinvention will therefore be generally limited to the longer staple glassfibers. Where fire resistance is not an important factor, it may bepossible within the scope of the invention to produce insulationmaterials from longer wood fibers and similar cellulosic fibers such ascotton fibers.

While asphalt has been mentioned as a desirable bonding agent, it willbe understood that other equivalent, generally pliable materials havinghigh adhesive retention over extended periods of time, can also be used.Such materials would include rubber based adhesives and the like havingvolatile solvents as vehicle. However, it has been found that careshould be exercised in the complete removal of the solvents of aflammable nature.

Kraft paper particularly desired for use in the present invention is asulphate kraft of natural brown color of about thirty pounds reamWeight. Aluminum foil for the foil-kraft laminate is preferably about0.00025 inch thick, preferably laminated to the paper with sodiumsilicate. Of course, the invention is not to be limited to sodiumsilicate as the only laminating material. Where cost is not a limitingfactor, heavier foils and papers can be used.

While the foregoing disclosure has related to strips of adhesive,characterizing economical and effective commercial production, it is tobe understood that spaced spots of adhesive also can be used within thebroadened scope of invention.

Vent hole size on the cold-side are preferably as small as possible foroptimum reflectivity and good vapor transmission. While hole size is notnecesarily critical, they are preferably formed by lancing to avoidremoving material.

Advantages of the present invention Advantages of the present inventionare believed to be self-evident from the foregoing description; however,they are briefly enumerated as follows:

(1) Higher thermal eificiency.

(2) The use of double foil for increased reflectivity yet preservingeconomies of production by omitting bridging foil-paper laminates orpapers along the lateral edges of the fibrous batt.

(3) Improved insulation by more intimate contact between the exposedlateral edges of the batt and building structural members.

(4) Improved thickness recovery after compression packaging.

(5) A lighter weight product, reducing manufacturing and Shipping costswith resultant advantages to both manufacturer and consumer.

(6) Improved thickness retention in use with retained high thermalefliciency.

(7) Optional nailing tabs at both surfaces for improved retention ofinsulating air spaces over the life of the product.

(8) Production advantage over the prior art that the problems inherentin envelope formation are obviated.

(9) Improved packaging efiiciency with no edge losses or defects aspreviously encounteredthere is no edge crumpling to damage the productwhile forcing compressed batts into a packaging tube.

(10) Also, an unexpected result is provided by removal of the lateraledge bridge. Thus improved processing and thickness recovery aftercompression packaging are provided-with lesser material weightar1dhigher thermal efficiency.

I claim:

1. In a thermal insulating material,

a coherent batt of long staple glass wool fibers positioned in randomoriented interlay and joined to one another at point contact by curedthermosetting phenolic resin,

said batt having opposed major surfaces of rectangular shape and lateraledges of rectangular shape,

said edges being free of covering,

an imperforate kraft-roll laminate secured to one of said major surfacesby adhesive between said surface and laminate and with the foil exposed,

said laminate comprising about 30 lbs/ream natural brown sulphite paperand aluminum foil of a thickness of 0.00025 inch bonded with sodiumsilicate,

a kraft-foil laminate as defined above, and also perforated, secured tothe other major surface by adhesive between said surface and laminateand with the foil exposed,

said perforated laminate having about 9025 punctures per square foot,

a major portion of said punctures being open to permit said batt tobreath to the ambient atmosphere,

and said imperforate laminate extending beyond said edges to formfastening tabs.

2. In a thermal insulating material,

a coherent, self-sustaining flexible, porous batt of glass Wool fiberspositioned at random oriented interlay and joined to one another atpoint contact by cured thermosetting phenolic resin and containing amultiplicity of air spaces,

said batt having opposed major surfaces of rectangular shape and opposedlateral edges of rectangular shape,

said edges being free of covering,

a sheet of kraft paper secured to one of said major surfaces by asubstantially continuous layer of asphalt,

said paper extending beyond said edges to provide fastening tabs,

a kraft-foil laminate secured to the other major surface by parallelstrips of asphalt and With the foil exposed,

said laminate comprising about 30 lb./ream natural brown sulphite paperand aluminum foil of a thickness of 0.00025 inch bonded with sodiumsilicate.

and said laminate having about 9025 punctures per square foot and with amajor portion of said punctures open to permit moisture vapor to pass atambient temperatures.

3. In a thermal insulating material,

a coherent batt of long staple glass Wool fibers positioned in randomoriented interl-ay and joined to one another at point contact by curedthermosetting phenolic resin,

said batt having opposed major surfaces of rectangular shape and opposedlateral edges of rectangular shape,

said edges being free of covering,

an imperforate kraft-foil laminate secured to one of said major surfacesby a substantially continuous layer of asphalt and with the foilexposed,

said laminate comprising about 30 lbs. per ream natural brown sulphitepaper and aluminum foil of 0.00025 inch bonded with sodium silicate,

a perforated kraft-foil laminate as defined above, se-

cured to the other major surface by parallel strips of asphalt with thefoil exposed,

said perforated laminate extending beyond said edges to providefastening tabs,

and said perforated laminate having about 9025 punctures per squarefoot, With a major portion of said punctures open to permit moisturevapor to pass freely at ambient temperatures.

4. In a thermal insulating material,

a coherent batt of long staple glass wool fibers positioned in randomoriented interlay and joined to one another at point contact by curedthermosetting phenolic resin,

said batt having opposed major surfaces of rectangular shape and opposededges of rectangular shape,

said edges being free of covering,

an imperforate kraft-foil laminate secured to one of said major surfacesby a substantially continuous layer of asphalt with the foil exposed,

said laminate comprising about 30 lbs. per ream natural brown sulphitepaper and aluminum foil of about 000025 inch thickness bonded withsodium silicate,

a perforated kraft-foil laminate as defined above, se-

cured to the other major surface by parallel strips of asphalt with thefoil exposed,

each of said laminates extending beyond said edges to provide fasteningtabs,

and said perforated laminate having about 9025 punctures per squarefoot.

References Cited by the Examiner UNITED STATES PATENTS 1,914,345 6/1933Roos 154-44 2,030,668 2/1936 Weyerhaeuser et al. 154-44 2,172,048 9/1939 Johnson 154-44 2,640,004 5/ 1953 Van Saun 156291 X 2,998,337 8/1961Tillotson 161-113 X 3,097,124 7/1963 Denenberg 161-113 ALEXANDER WYMAN,Primary Examiner. EARL M. BERGERT, MORRIS SUSSMAN, Examiners.

1. IN A THERMAL INSULATING MATERIAL, A COHERENT BATT OF LONG STAPLEGLASS WOOL FIBERS POSITIONED IN RANDOM ORIENTED INTERLAY AND JOINED TOONE ANOTHER AT POINT CONTACT BY CURED THERMOSETTING PHENOLIC RESIN, SAIDBATT HAVING OPPOSED MAJOR SURFACES OF RECTANGULAR SHAPE AND LATERALEDGES OF RECTANGULAR SHAPE, SAID EDGES BEING FREE OF COVERING, ANIMPERFORATE KRAFT-ROLL LAMINATE SECURED TO ONE OF SAID MAJOR SURFACES BYADHESIVE BETWEEN SAID SURFACE AND LAMINATE AND WITH THE FOIL EXPOSED,SAID LAMINATE COMPRISING ABOUT 30 LBS,/REAM NATURAL BROWN SULPHITE PAPERAND ALUMINUM FOIL OF A THICKNESS OF 0.00025 INCH BONDED WITH SODIUMSILICATE,